Stethoscope for automobiles.



A. DE GLAIRMONT.

STBTHOSCOPB FOB AUTOMOBILES. APPLICATION FILED. APB-.15, 1013.

1,107,212. Patented Aug. 11, .1914,

.3 t z J. EeCla irmg I am UNITED STATEbl OFFICE.

ADOLFO m: CLAIRMONT, OF TOLEDO, OHIO.

STETI-IOSCOPE FOR AUTOMOBILES.

To all whom, it may concern:

Be it known that LAnoLro DE CLAIRMON'I, citizen of the United States, residing at T oledo, in the county of Lucas and State of Ohio, have invented certain new and useful Improvements in Stethoscopes for Automobiles, of which the following is a specification.

My invention relates to devices for andibly detecting and locating mal-adjustments, faults and imperfect working in motor cars, and particularly to what may be termed stethoscopes whereby imperfect working and noises duethereto may be lo cated.

, To an experienced car driver, the car speaks a language of its own, significant and definite and telling plainly of any faults or defects that there may be in the running parts. These faults and imperfections are sometimes so slight that the accompanying sound is too faint to be distinctly heard and differentiated by the unaided ear.

Itis the object of my invention to provide a simple, cheap and extremely effective device or stethoscope whereby very faint sounds such as those made by loose wrist pins or slightly untrue motor bearings may be detected and differentiated from the normal sounds produced by the mechanism in action.

A further object is to so construct the stethoscope that the sound carried to the ear shall be distinct rather than very loud, thus avoiding the objections of the ordinary tubular stethoscope in which the' sound is carried to the ear in too greatavolume and is thus rendered confused and jumbled.

In carrying out my invention, I take advantage of the very high sound conductivity of sugar pine as a means of transmitting sound and of the sound conductivity of aluminum as a means of selecting metallic sounds such as are caused by contact of metallic members.

My invention is illustrated in the accompanying drawings wherein:

Figure l is a perspective view of my improved stethoscope; Fig. 2 is a section.

In carrying out my invention I use a wooden rod 2 preferably formed of what is known as sugar pine, this rod being preferably tapering and of any suitable length. I have found in practice that the rod is best made about three-fourths of an inch in diameter at its larger end and tapers to one- Specification of Letters Patent.

Application filed April 15, 1913.

. Patented Aug. 11, 1914.

Serial No. 761,393.

half inch at its smaller end. Attached to its smaller end is an aluminum tip 3. This tip is approximately conoidal in form so as to present a relatively small or sharp apex and at its base is formed with a screwthreaded tang L which is forced into the wood of the rod 2. The rod is prevented from splitting by a ferrule 5 also of aluminum. At its larger end the rod is connected to a sound transmitting disk or sound board 6 also of wood and preferably of pine wood and which is preferably formed integral with the rod 2.

In order to more fully transmit the sound traveling along the rod to the sound board or disk (3, I insert into the wood of the disk an aluminum pin 7 preferably formed with an enlarged head 8 which is received in a recess in the outer face of the disk 6 so that the outer face of the head is llush with the outer face of the disk. The wooden disk 6 constitutes the sound box, sound board or resonator. By means of this combination of pine and aluminum I secure a perfect transmission of sounds and particularly of metalhe sounds. The device, therefore, not only acts as a sound transmitter but as a sound selector. This is due to the aluminum tip and the aluminum button or disk 8 whose mole cules vibrate best to metallic sounds and are most sympathetic thereto. The pine sound transmitting rod carries the sound to the sounding board or disk 6, and here again the metallic sounds effect certain vibration on the disk 8. I have found by experience that no other wood answers quite as well for the purpose of transmitting these sounds as pine and particularly sugar pine, and no other metal than aluminum has quite the peculiar capacity for this purpose. By reason of the tip 3 being pointed, sounds may be quickly located and this because only an extremely small point of contact is provided between the tip and the part which is applied.

It will be noted that I have provided a combination whereby metallic sounds are selected from other sounds due to the normal action of the machinery and whereby the sounds are readily transmitted. It will be noted that the wooden rod is used because of the perfection of the transmission secured thereby and that a wooden disk or resonator is used because wood is more resonant and secures a greater distinctness of sound than is possible with metal alone.

In use the wooden disk is placed to the ear. The shell of the ear and the wooden disk thus form a sound box. The point of the tip is now applied to a metallic part where it is desired to locate a fault and moved about until the sound caused by an imperfection is most clearly heard. I have found in practice that sounds may be located with extreme accuracy and readiness by means of my construction.

The wood which I refer to as sugar pine, and from which I prefer to make the transmitting rod, is very soft and homogeneous, of a white color without any sap, and has the smell of sugar when freshly cut. The wood is capable of being dried thoroughly and contains rather large cells containing air. These cells apparently act as resonators to transmitthe sound, and it is for this reason that this wood is particularly adapted for my purpose. Aluminum itself isalso a wonderful conductor of sound and in combination with the wood conveys the sound to the wood transmitter and from the wood transmitter to the ear in a much more distinct manner than if the wood were used alone. In actual use, the aluminum point or tip receives the coarse metallic vibrations of the engine and transmits the sound waves to the sugar pine transmitter. These sound waves are there modified and passed along the rod to the aluminum disk and pin which again receives the metallic sounds and distributes the same to the sound box formed by the circular disk. The combination of aluminum and sugar pine allows, therefore, to ahigh degree sound waves to ,be transmitted with full intensity to the car. It is possible by heavy pressure against the machinery and a light pressure of the resonator to the shell of the ear to differentiate heavy noises, slight squeaks, scrapings or even the blow-out indicated by leaky valves.

The differentiation of these noises depends upon the amount of pressure with which the tip is held against the machinery and the amount of pressure with which the resonator is held against the ear.

It will be noted that the wooden rod and tip form the transmitter, and that the wooden and aluminum disks together form an amplifier.

Having described my invention, what I claim as new is:

l. Astethoscope of the character described including a rod of fibrous material, a disk of fibrous material forming one end of said rod, a metallic tip forming the opposite terminal of said rod and a metallic member inserted within the face of the disk, said rod forming a sound conducting medium between the metallic tip and the metallic member in the disk.

2. Astethoscope of the character described, including a' wooden rod having a pointed metallic tip, the base of said rod being formed to provide a disk relatively large in diameter, said disk forming a sounding board, said disk being rigid and rigidly connected to the rod.

3. Astethoscope of the character described, including a wooden rod, one end of which is tapered, the other end being formed to provide a wooden disk having a relatively large diameter, a metallic disk and integral pin inserted in the wooden disk, the face of the metallic disk lying flush with the face of the wooden disk, and a metallic tip forming the terminal end of the wooden rod and having a portion inserted into said wooden rod.

In testimony whereof ll afiiX my signature in presence of two witnesses.

ADOLFO DE CLAlltlllONT. [L 3.] Witnesses:

E. M. KEINATH, H. WALrnRs, 

